I have used a R5-100, 5 HP, 62 CFM pump for 5 seasons.
Pros: Makes great vacuum very fast, plenty of CFM's for 2,360 taps
Pretty bullet proof. First season mechanical moisture trap failed and unit was pumping sap out exhaust. Changed oil and filters, works fine
Pump will run continuously for days on end making high vacuum
Cons: Needs to be in a heated room (50 degrees) in order to start without stressing the unit. That is OK, I have an electric moisture trap that has to be in a warm room too.
Pump makes quite a bit of heat and you have to keep the vacuum room door open on warmer days with a fan blowing on pump
You cannot run the pump with the vacuum level under 22". The unit will blow the oil out the exhaust. Almost ruined the pump 3 times before I got the problem solved
Oil is very expensive. At Lapierre, $32.00 a quart, pump requires 2 quarts. For this season, I found the oil at Boston Vacuum for $19.00 a gallon plus shipping
Interior oil filters are very expensive. Requires 2 filters at $60.00 apiece
Must have an electric moisture trap (which I found out after the mechanical trap failed)
I do not like the Lovejoy fitting between the pump head and the motor. I have had to replace it once. Not an easy fix
The oil return line from the pump head to the reservoir is too small. Had to replace with a larger line.
If I knew all this stuff before I bought the R-5, I would have gone with a two stage Sihi oil cooled liquid ring pump like the one at my sugar house. It is pretty much care free. Change the oil yearly and drain any water out of the bottom of the oil cooler daily. The Sihi does not have as high a CFM output, but makes high vacuum and I have not had a problem in 8 season with it.
Joe
2004- 470 taps on gravity and buckets
2006- 590 taps on gravity and buckets 300 gph RO
2009- 845 taps on vacuum no buckets, 600 gph RO
2010- 925 taps on vacuum new 2 stage vacuum pump
2014- 3045 taps on vacuum, new 1200 gph RO
2015- 3104 taps on vacuum
2017- 3213 taps on vacuum
3' x 10' oil fired evaporator with steamaway